1. Field of the Invention
The present invention relates to a disk array system, and more particularly, a disk array system that enables replacement of a disk array device without terminating operation.
2. Description of the Related Art
There is known a disk array system comprising plural disk array devices each having two disk array controllers (DACs). According to such a disk array system, the two DACs in each disk array device generally has a redundant configuration (see, for example, Unexamined Japanese Patent Application KOKAI Publication No. 2007-086941).
Accordingly, as shown in FIG. 6, when, for example, the backboard of a disk array device 10-(N−2) breaks down so that it becomes necessary to replace the disk array device 10-(N−2), it is necessary to terminate operation of the disk array system, because both DACs 12A-(N−2) and 12B-(N−2) become inoperative.
In other words, it is impossible to replace the disk array device 10-(N−2) while the disk array system is in operation.